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Antimicrobial Agents and Chemotherapy Mar 1997Polyomavirus infections in humans are due to BK virus (BKV) and JC virus (JCV). Diseases associated with human polyomaviruses occur mostly in immunocompromised adults,...
Polyomavirus infections in humans are due to BK virus (BKV) and JC virus (JCV). Diseases associated with human polyomaviruses occur mostly in immunocompromised adults, e.g., progressive multifocal leukoencephalopathy (PML), caused by JCV, in AIDS patients and hemorrhagic cystitis and uretral stenosis, caused by BKV, in transplant recipients. No therapy is available for these diseases, which necessitates the development of chemical entities that are active against polyomaviruses. Several antiviral compounds were evaluated to determine their effects on the in vitro replication of mouse polyomavirus and the primate viruses simian virus 40 (SV40), SV40 PML-1, and SV40 PML-2. The activity of the different compounds was assessed by a cytopathic effect reduction assay and confirmed in a virus yield assay. Cidofovir [HPMPC; (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine] and its cyclic counterpart emerged as the most selective antipolyomavirus agents. The 50% inhibitory concentrations for HPMPC were in the range of 4 to 7 micrograms/ml, and its selectivity index varied from 11 to 20 for mouse polyomavirus and from 23 to 33 for SV40 strains in confluent cell monolayers. Cell cytotoxicity was up to 15-fold greater in growing cells. Other acyclic nucleoside phosphonates (i.e., HPMPA; [(S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine] and PMEG [9-(2-phosphonylmethoxyethyl)-guanine]) also showed some activity but had low selectivity. None of the other drugs tested against these animal viruses (i.e., acyclovir, ganciclovir, brivudine, ribavirin, foscarnet, and cytarabine) showed significant activity. Thus, HPMPC deserves further evaluation as a candidate drug for polyomavirus infections in the immunocompromised host.
Topics: Animals; Antiviral Agents; Cell Line; Cell Survival; Chlorocebus aethiops; Cidofovir; Cytosine; Mice; Organophosphonates; Organophosphorus Compounds; Polyomavirus; Polyomavirus Infections; Simian virus 40; Virus Replication
PubMed: 9055998
DOI: 10.1128/AAC.41.3.587 -
Antiviral Research Oct 2014The alphaherpesvirus varicella-zoster virus (VZV) causes chickenpox and shingles. Current treatments are acyclovir (ACV) and its derivatives, foscarnet and brivudine...
β-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU) prevents varicella-zoster virus replication in a SCID-Hu mouse model and does not interfere with 5-fluorouracil catabolism.
The alphaherpesvirus varicella-zoster virus (VZV) causes chickenpox and shingles. Current treatments are acyclovir (ACV) and its derivatives, foscarnet and brivudine (BVdU). Additional antiviral compounds with increased potency and specificity are needed to treat VZV, especially to treat post-herpetic neuralgia. We evaluated β-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU, 1) and 5'-O-valyl-l-BHDU (2) in three models of VZV replication: primary human foreskin fibroblasts (HFFs), skin organ culture (SOC) and in SCID-Hu mice with skin xenografts. The efficacy of l-BHDU in vivo and its drug-drug interactions were previously not known. In HFFs, 200μM l-BHDU was noncytotoxic over 3days, and l-BHDU treatment reduced VZV genome copy number and cell to cell spread. The EC50 in HFFs for l-BHDU and valyl-l-BHDU were 0.22 and 0.03μM, respectively. However, l-BHDU antagonized the activity of ACV, BVdU and foscarnet in cultured cells. Given its similar structure to BVdU, we asked if l-BHDU, like BVdU, inhibits 5-fluorouracil catabolism. BALB/c mice were treated with 5-FU alone or in combination with l-BHDU or BVdU. l-BHDU did not interfere with 5-FU catabolism. In SCID-Hu mice implanted with human skin xenografts, l-BHDU and valyl-l-BHDU were superior to ACV and valacyclovir. The maximum concentration (Cmax) levels of l-BHDU were determined in mouse and human tissues at 2h after dosing, and comparison of concentration ratios of tissue to plasma indicated saturation of uptake at the highest dose. For the first time, an l-nucleoside analog, l-BHDU, was found to be effective and well tolerated in mice.
Topics: Acyclovir; Animals; Antiviral Agents; Bromodeoxyuridine; Cell Line; Chickenpox; Dioxolanes; Drug Therapy, Combination; Fluorouracil; Foscarnet; Herpes Zoster; Herpesvirus 3, Human; Humans; Mice; Mice, Inbred BALB C; Mice, SCID; Nucleosides; Organ Culture Techniques; Skin; Uracil; Virus Replication
PubMed: 25051026
DOI: 10.1016/j.antiviral.2014.07.007 -
Viruses May 2021Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed...
Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed murine γ-herpesvirus-68 (MHV-68) that efficiently replicates in vitro as a model to study the antiviral resistance of γ-herpesviruses. In this study, we investigated the mechanism of resistance to nucleoside (ganciclovir (GCV)), nucleotide (cidofovir (CDV), HPMP-5azaC, HPMPO-DAPy) and pyrophosphate (foscarnet (PFA)) analogues and the impact of these drug resistance mutations on viral fitness. Viral fitness was determined by dual infection competition assays, where MHV-68 drug-resistant viral clones competed with the wild-type virus in the absence and presence of antivirals. Using next-generation sequencing, the composition of the viral populations was determined at the time of infection and after 5 days of growth. Antiviral drug resistance selection resulted in clones harboring mutations in the viral DNA polymerase (DP), denoted Y383S, Q827R, G302W, K442T, G302W+K442T, C297W and C981Y. Without antiviral pressure, viral clones Q827R, G302W, K442T and G302W+K442T grew equal to the wild-type virus. However, in the presence of antivirals, these mutants had a growth advantage over the wild-type virus that was moderately to very strongly correlated with antiviral resistance. The Y383S mutant was more fit than the wild-type virus with and without antivirals, except in the presence of brivudin. The C297W and C981Y changes were associated with a mutator phenotype and had a severely impaired viral fitness in the absence and presence of antivirals. The mutator phenotype caused by C297W in MHV-68 DP was validated by using a CRISPR/Cas9 genome editing approach.
Topics: Amino Acid Substitution; Animals; CRISPR-Cas Systems; Cell Line; Codon; DNA-Directed DNA Polymerase; Gene Editing; Genes, Viral; Genetic Fitness; Genotype; Humans; Mice; Models, Molecular; Mutation; Phenotype; Protein Conformation; Rhadinovirus; Structure-Activity Relationship
PubMed: 34073189
DOI: 10.3390/v13060985 -
Scientific Reports Mar 2017Dendritic cells (DCs) play a critical role in the pathogenesis of autoimmune diseases including multiple sclerosis, and targeting DCs' cytokines production is an...
Dendritic cells (DCs) play a critical role in the pathogenesis of autoimmune diseases including multiple sclerosis, and targeting DCs' cytokines production is an important strategy for autoimmune diseases treatment. By establishing a high-throughput screening system, we analyzed LOPAC drug library to identify drugs that control the secretion of IL-6 by DCs, we selected the most likely candidate drug, BVDU, and found that it affected not only IL-6 production, but also that of IL-12, IL-1β during the DCs differentiation and maturation. The mechanism studies showed that BVDU treatment restricted the phosphorylation of MAP kinase, which played an important role in DC cytokine production. We further assessed the in vivo therapeutic potentials of BVDU on mouse models including EAE and STZ-induced T1D, and found that BVDU treated EAE mice exhibited significantly lower EAE clinical scores, decreased leukocyte infiltration in central nervous system lesions, and reduced demyelination. As in T1D mice, BVDU treatment also showed promising therapeutic effects based on both alleviated disease symptoms and tissue pathogenesis. More interestingly, the modulating effect of BVDU on IL-6 production was further verified in human primary DCs. The above data supported the promising application of our screen model, and also the potential of BVDU for autoimmune diseases therapy.
Topics: Animals; Autoimmune Diseases; Bromodeoxyuridine; Cell Differentiation; Dendritic Cells; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Drug Discovery; Encephalomyelitis, Autoimmune, Experimental; Humans; Interleukin-12; Interleukin-1beta; Interleukin-6; Mice, Inbred C57BL
PubMed: 28272439
DOI: 10.1038/srep43820 -
Farmacia Hospitalaria : Organo Oficial... 2013
Topics: Antimetabolites; Antiviral Agents; Bromodeoxyuridine; Female; Fluorouracil; Humans
PubMed: 24010699
DOI: 10.7399/FH.2013.37.4.694 -
Organotypic epithelial raft cultures as a model for evaluating compounds against alphaherpesviruses.Antimicrobial Agents and Chemotherapy Nov 2005The course of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) and varicella-zoster virus (VZV) infections in squamous epithelial cells cultured in a...
The course of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) and varicella-zoster virus (VZV) infections in squamous epithelial cells cultured in a three-dimensional organotypic raft culture was tested. In these raft cultures, normal human keratinocytes isolated from neonatal foreskins grown at the air-liquid interface stratified and differentiated, reproducing a fully differentiated epithelium. Typical cytopathic changes identical to those found in the squamous epithelium in vivo, including ballooning and reticular degeneration with the formation of multinucleate cells, were observed throughout the raft following infection with HSV and VZV at different times after lifting the cultures to the air-liquid interface. For VZV, the aspects of the lesions depended on the stage of differentiation of the organotypic cultures. The activity of reference antiviral agents, acyclovir (ACV), penciclovir (PCV), brivudin (BVDU), foscarnet (PFA), and cidofovir (CDV), was evaluated against wild-type and thymidine kinase (TK) mutants of HSV and VZV in the raft cultures. ACV, PCV, and BVDU protected the epithelium against cytopathic effect induced by wild-type viruses in a concentration-dependent manner, while treatment with CDV and PFA proved protective against the cytodestructive effects induced by both TK+ and TK- strains. The quantification of the antiviral effects in the rafts were accomplished by measuring viral titers by plaque assay for HSV and by measuring viral DNA load by real-time PCR for VZV. A correlation between the degree of protection as determined by histological examination and viral quantification could be demonstrated The three-dimensional epithelial raft culture represents a novel model for the study of antiviral agents active against HSV and VZV. Since no animal model is available for the evaluation of antiviral agents against VZV, the organotypic cultures may be considered a model to evaluate the efficacy of new anti-VZV antivirals before clinical trials.
Topics: Alphaherpesvirinae; Animals; Antiviral Agents; Cell Differentiation; Cells, Cultured; Epithelial Cells; Humans; Keratinocytes; Mice; Swiss 3T3 Cells
PubMed: 16251311
DOI: 10.1128/AAC.49.11.4671-4680.2005 -
Journal of Virology Feb 2020Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of three human malignancies: Kaposi's sarcoma, primary effusion lymphoma, and the plasma cell variant of...
Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of three human malignancies: Kaposi's sarcoma, primary effusion lymphoma, and the plasma cell variant of multicentric Castleman disease. Previous research has shown that several cellular tyrosine kinases play crucial roles during several steps in the virus replication cycle. Two KSHV proteins also have protein kinase function: open reading frame (ORF) 36 encodes a serine-threonine kinase, while ORF21 encodes a thymidine kinase (TK), which has recently been found to be an efficient tyrosine kinase. In this study, we explore the role of the ORF21 tyrosine kinase function in KSHV lytic replication. By generating a recombinant KSHV mutant with an enzymatically inactive ORF21 protein, we show that the tyrosine kinase function of ORF21/TK is not required for the progression of the lytic replication in tissue culture but that it is essential for the phosphorylation and activation to toxic moieties of the antiviral drugs zidovudine and brivudine. In addition, we identify several tyrosine kinase inhibitors, already in clinical use against human malignancies, which potently inhibit not only ORF21 TK kinase function but also viral lytic reactivation and the development of KSHV-infected endothelial tumors in mice. Since they target both cellular tyrosine kinases and a viral kinase, some of these compounds might find a use in the treatment of KSHV-associated malignancies. Our findings address the role of KSHV ORF21 as a tyrosine kinase during lytic replication and the activation of prodrugs in KSHV-infected cells. We also show the potential of selected clinically approved tyrosine kinase inhibitors to inhibit KSHV TK, KSHV lytic replication, infectious virion release, and the development of an endothelial tumor. Since they target both cellular tyrosine kinases supporting productive viral replication and a viral kinase, these drugs, which are already approved for clinical use, may be suitable for repurposing for the treatment of KSHV-related tumors in AIDS patients or transplant recipients.
Topics: Animals; Cell Line; Cell Survival; Chlorocebus aethiops; Gene Expression Regulation, Viral; HEK293 Cells; Herpesvirus 8, Human; Humans; Mice; Mutation; Open Reading Frames; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Sarcoma, Kaposi; Vero Cells; Virus Latency; Virus Replication
PubMed: 31826996
DOI: 10.1128/JVI.01791-19 -
Scientific Reports Jul 2016Here, we describe a novel reliable method to assess the significance of individual mutations within the thymidine kinase (TK) gene of herpes simplex virus type 1 (HSV-1)...
Here, we describe a novel reliable method to assess the significance of individual mutations within the thymidine kinase (TK) gene of herpes simplex virus type 1 (HSV-1) to nucleoside analogue resistance. Eleven defined single nucleotide polymorphisms that occur in the TK gene of clinical HSV-1 isolates and a fluorescence reporter were introduced into the HSV-1 strain 17(+) that had been cloned into a bacterial artificial chromosome. The susceptibility of these different strains to aciclovir, penciclovir, brivudin, and foscarnet was determined with a modified cytopathic effect reduction assay. The strains were also tested for their aciclovir susceptibility by measuring the relative fluorescence intensity as an indicator for HSV-1 replication and by quantifying the virus yield. Our data indicate that the amino acid substitutions R41H, R106H, A118V, L139V, K219T, S276R, L298R, S345P, and V348I represent natural polymorphisms of the TK protein, whereas G61A and P84L mediate broad cross-resistance against aciclovir, penciclovir, brivudin, and susceptibility to foscarnet. This method allows the definition of the resistance genotype of otherwise unclear mutations in the TK gene of HSV-1. Thus, it provides a scientific basis for antiviral testing in clinical isolates of patients suffering from serious diseases and will facilitate testing of new antivirals against HSV-1.
Topics: Acyclovir; Animals; Antiviral Agents; Chlorocebus aethiops; Drug Resistance, Viral; Herpesvirus 1, Human; Kinetics; Mutation; Polymerase Chain Reaction; Recombination, Genetic; Thymidine Kinase; Transfection; Vero Cells; Viral Load; Virus Replication
PubMed: 27426251
DOI: 10.1038/srep29903 -
Proceedings of the National Academy of... May 1981Bromovinyldeoxyuridine (BVdUrd) is a potent antiherpesvirus compound with low cytotoxicity. To gain an insight into its selectivity and mechanism of inhibition, we...
Bromovinyldeoxyuridine (BVdUrd) is a potent antiherpesvirus compound with low cytotoxicity. To gain an insight into its selectivity and mechanism of inhibition, we chemically synthesized the 5'-triphosphate of BVdUrd, BVdUTP, and tested its effect on the activities of DNA polymerases [DNA nucleotidyltransferase (DNA directed), EC 2.7.7.7] of two herpesviruses--i.e., herpes simplex virus type 1 (HSV-1) and Epstein-Barr virus (EBV)--as well as cellular DNA polymerases alpha, beta, and gamma. The effects on the DNA polymerases were determined under assay conditions optimal for the individual polymerases. We found that the BVdUTP was considerably more inhibityory to the utilization of dTTP by the HSV-1 DNA polymerase then by the cellular DNA polymerases. For instance, as little as 1 microM BVdUTP inhibited the utilization of dTTP by HSV-1 DNA polymerase 50%, whereas the same concentration inhibited the DNA polymerase alpha and the DNA polymerase beta activities only 9% and 3%, respectively. The BVdUTP inhibited DNA synthesis by competing with the natural substrate, dTTP. The Km for dTTP and the Ki for the BVdUTP of the HSV-1 DNA polymerase were 0.66 and 0.25 microM, respectively. Kinetic analyses with the DNA polymerases alpha and beta and the EBV DNA polymerase also reflected a similar difference in sensitivity between the HSV-1 enzyme and other enzymes. Increasing the concentration of either the DNA template or the enzyme in the reaction mixture did not bring about a significant change in the extent of inhibition. Preincubation of the inhibitor with the enzyme was not necessary for inhibition. Studies on time course of inhibition revealed that the compound is inhibitory even after the initiation of DNA synthesis. These studies indicate that the ability of BVdUTP to preferentially inhibit the HSV-1 DNA polymerase may contribute towards its selective inhibition of the viral DNA replication in infected cells.
Topics: Antiviral Agents; Bromodeoxyuridine; Carcinoma; Cell Line; DNA Polymerase II; DNA-Directed DNA Polymerase; Humans; Kinetics; Mouth Neoplasms; Simplexvirus; Virus Replication
PubMed: 6265902
DOI: 10.1073/pnas.78.5.2698 -
Antimicrobial Agents and Chemotherapy Aug 1979The pharmacokinetics of the newly developed anti-herpes agent, E-5-(2-bromovinyl)-2'-deoxyuridine, was compared with that of the standard anti-herpes drug... (Comparative Study)
Comparative Study
The pharmacokinetics of the newly developed anti-herpes agent, E-5-(2-bromovinyl)-2'-deoxyuridine, was compared with that of the standard anti-herpes drug 5-iodo-2'-deoxyuridine. Both compounds were administered to mice at 100 mg/kg by either the intraperitoneal, subcutaneous, or oral route. The active blood drug levels achieved by E-5-(2-bromovinyl)-2'-deoxyuridine were considerably higher than those attained by 5-iodo-2'-deoxyuridine (serum peak concentrations: 40 to 100 and 4 to 10 mug/ml, respectively). Active blood drug levels could still be found 320 min after oral administration of E-5-(2-bromovinyl)-2'-deoxyuridine.
Topics: Animals; Antiviral Agents; Brain Chemistry; Bromodeoxyuridine; Floxuridine; Idoxuridine; Kinetics; Liver; Lung; Mice; Simplexvirus
PubMed: 225987
DOI: 10.1128/AAC.16.2.234